Soot eliminator



Oct. 22, 1968 LE ROY F. DEMING SOOT ELIMINATOR Filed Sept. 22. 1965 FIG.

INVENTOR. LELROY F. DEMING ATTORNEY.

United States Patent 3,406,500 SOOT ELIMINATOR Le Roy F. Deming, 151217th St. N.,

Arlington, Va. 22209 Filed Sept. 22, 1965, Ser. No. 489,438 4 Claims.(Cl. 55-241) ABSTRACT OF THE DISCLOSURE A soot eliminator which isadapted to remove soot particles which are heavier than the gases whichentrain such particles. The eliminator utilizes an impeller whichrotates in a smoke column within a hollow cylindrical collector. Theimpeller throws, by centrifugal force, the soot particles against theinner wall of the collector where a wall of water is provided to entrainthe particles and carry them to a disposal area.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

Air pollution is becoming an increasing problem in the various citiesthroughout the United States. Since a good portion of this pollution iscaused by smoke emanating from boilers, incinerators, foundries, and soforth considerable research is still being undertaken to come up withnew methods of preventing this smoke from being dissipated into the air.In some areas the pollution concentration becomes so great that it isconsidered dangerous and an alert is called to require all manufacturingplants to switch their heating means from coal or fuel oil to gas.Therefore, there is a need for an effective soot eliminator which can beeasily adapted to a boiler outlet, incinerator, and so forth forremoving the soot from the smoke stream emanating therefrom.

The present invention provides a compact simply constructed sooteliminator which will effectively remove the soot from a smoke stream.The present soot eliminator is adapted to be mounted within the normalstream of the smoke column and is self-cleaning so that costlymaintenance is not required. The present soot eliminator may include ahollow cylindrical soot collector which has a bottom smoke receivinginlet and a top gas discharge outlet. Mounted within the hollow cylindercollector there may be an impeller means for centrifugally forcing thesoot to the inner wall of the cylinder. Also mounted within thecollector there may be a means for discharging wash water over thecollectors inner wall so that the soot particles located thereat arewashed downwardly. Mounted within the collector above the waterdischarging means there may be a means for trapping water particles andreturning them to the Water discharging means. In this manner waterparticles which remain in the upwardly flowing gases after the washingprocess will be recovered and returned to the water discharging means.An exit duct may be connected to the collectors top outlet for receivingthe clean gas and a bafile means may be mounted within this duct forimpeding any circular motion of this gas as it continues its upwardflow.

An object of the present invention is to provide a soot eliminator whichis capable of more efiiciently removing soot particles from smokeemanating from a boiler outlet, incinerator and the like;

Another object is to provide a soot eliminator which employs a washwater technique and which is adapted to be connected to a smokeemanating device along the normal upward flow of said smoke;

A further object is to provide a soot eliminator which employs a Washwater technique wherein water remain- 3,406,500 Patented Oct. 22, 1968ing in the cleaned gases is recoverable and returnable for the washingprocess;

Still another object is to provide a soot eliminator which forceablymixes soot particles with wash water and yet discharges the cleanedgases with a minimum of turbulence; and

Other objects, advantages and novel features of the invention willbecome apparent from the following detailed description of the inventionwhen considered in conjunction with the accompanying drawing wherein:

FIG. 1 is an elevational side view of the soot eliminator with portionscut away to show the details thereof;

FIG. 2 is a cross sectional view taken along plane II-II of FIG. 1;

FIG. 3 is a cross sectional view taken along plane III-III of FIG. 1;and

FIG. 4 is a cross sectional view taken along plane lV- IV of FIG. 1.

Referring now to the drawing wherein like reference numerals designatelike or similar parts throughout the several views there is shown inFIG. 1 the soot eliminator 10 which includes a hollow cylindrical sootcollector 12. The soot collector 12 includes a bottom smoke receivinginlet 14, which is capable of being connected to an outlet 16 of aboiler, incinerator or the like, and further includes a top gasdischarge outlet 18 with a gas column extending between the inlet andoutlet. Accordingly, as smoke exits the boiler outlet 16 it will passupwardly through the soot collector 12. Soot, for purposes of thisapplication, shall include all solids and particulate material entrainedin the gas or air stream, irrespective of the source, of whichthespecific gravity is greater than that of the gas entraining the materialand which is therefore adaptable to removal by centrifugal force in adevice such as is described herein.

Mounted within the collector 12 is a means for forcing the soot to theinner wall 20 of the collector 12. This means may include an elongatedmultiple vane impeller 22 which is rotatably mounted within thecollector 12 with its axis of rotation substantially aligned with thelongitudinal axis of the collector 12. The impeller shaft 24 may bejournalled within top and bottom bearings 26 and 28 which are mountedwithin the collector 12 by top and bottom spiders 30 and 32respectively, the spider '30 being transversely connected to thecollector across its outlet 18 and the spider 32 being transverselyconnected to the collector across the inlet 14.

The blades 34 of the impeller may be radially offset from the impellershaft 24 by a large diameter tube 36 which is connected to the impellershaft 24 by end plates 38. The blades 34 may be mounted to the tube 36by any suitable means such as welding. The tube 36 serves the purpose offilling the central space within the collector where the centrifugalforce on the column of soot particles would be at a minimum. A cone 40may be mounted on top of the large diameter tube 36 for protecting thehearing 26 from soot particles. A similar cone 42 may be mounted at thebottom of the tube 36 for protecting the bearing 28 and bafliing theupwardly traveling smoke into the impeller area.

In order to drive the impeller 22 a variable speed motor 44 may bemounted on the exterior of the collector 12 by a welded bracket 46 withthe motor shaft 48 extending transverse the collector and into the topcone 40. A right angle gear box 50 may be connected at the upperinterior end of the cone 40 by welding so as to receive the ends of themotor shaft 48 and the impeller shaft 24. It is now readily apparentthat when smoke travels upwardly within the collector 12 the impeller 22can be rotated at a desired speed by the motor 44 to centrifugally forcesoot particles in the column of smoke to the inner wall 20 of thecollector.

In order to capture the soot particles which have been centrifugallyforced to the inner wall 20 of the collector a means may be mountedwithin the collector for discharging wash water over this inner wall.The wash water discharging means may include an annular wash watersupply header 52 which is mounted integrally with the collector wall andintermediate the inlet and outlet 14 and 18. Connected to the header 52is a wash water supply conduit 54 which may be connected at an oppositeend to a fresh water supply source (not shown). The wash waterdischarging means may further include an annular perforated tube 56which is mounted adjacent to and circumferentially along the innerperiphery of the inner wall 20 of the collector a short distance belowthe header 52. The tube 56 may be provided with a series of downwardlyfacing perforations 58 which are adjacent the inner wall 20, the tube 56being connected to the header 52 by an annular conduit 69. Accordingly,the wash water is supplied to the annular tube 56 after which the waterexits through the many perforations 58 to provide a wall of water aboutthe inner wall 20 around the outer periphery of the gas column of thecollector 12. The outwardly thrown soot particles are mixed with thiswall of water and are carried downwardly Within the collector to anannular scavenging trough 62. The scavenging trough 62 may be integralwith the wall of the collector 12 and may be mounted at its inlet end14. A drain pipe 64 may be connected to the scavenging trough 62 fordraining the soot filled water to a sewer system, or to a filter whereit can be cleaned and made available for recirculation.

Because of the turbulence of the upwardly rising gaseous products withinthe collector 12 there may be some water particles entrained in the gasabove the annular tube 56. It is desirable that these water particles bere moved from the upwardly moving gas and returned to the wash waterheader 52. In order to accomplish this a means has been mounted withinthe collector above the wash water tube 56 for trapping the waterparticles and returning them to the header 52. The water trapping meansmay include an inner hollow cylinder 66 which is concentrically mountedin a spaced relationship within the collector 12 so as to provide anannular space 68 therebetween. Accordingly, the space 68 will provide adrain area for returning water to the header 52. The bottom end of thehollow cylinder 66 may be integrally connected with the header 52 and atop end of the cylinder 66 may be connected to the spider 30 by welding.Intermediate the top and bottom ends of the cylinder 66 are verticallyextending slots 70 which communicate the interior of the collector 12with the annular space 68. Accordingly, the upwardly rising waterparticles are centrifugally forced outwardly by the impeller 22 onto theinner surface of the cylinder 66 where the water particles will collectand run into the annular space 68 through the slots 70. The watercollected within the annular space 68 will then drain down the interiorwall 20 of the collector into the header 52 whereupon it will be fed tothe annular tube 56 for further washing purposes.

A slight amount of water may still be entrained within the circularmoving gaseous products as they leave the outlet end 18 of thecollector. It is desirable that as much of this water as possible bereturned to the collector so that it can be forced through the slots 70into the annular drain area 68. As shown in FIG. 1 an exit duct 72 isconnected to the upper outlet end 18 of the collector. This exit ductmay be connected at an opposite end to a chimney which will dissipatethe gases into the atmosphere. The water particles within the column ofgases in the exit duct 72 may be returned to the collector 12 by abattle means which is mounted within the exit duct for impeding thecircular motion of the gases. The baflle means may include a series ofbafiles 74 which are mounted to the inner wall of the exit duct 72 andwhich extend inwardly with a slight curve opposite to the cir- 4 cularmotion of the upwardly rising gases. These baffles 74 will slow thecircular motion of the gases thereby causing entrained water particlesto fall or drain into the collector 12 and within the cylinder 66 wherethey can be recovered for washing purposes.

The soot eliminator may be constructed mainly of sheet metal and metalparts. The various components may be connected together by any suitablemeans such as welding.

In the operation of the soot eliminator the upwardly rising smoke fromthe boiler outlet 16 is caused to undertake a high circumferentialvelocity within the collector 20 due to the action of the impeller 22.The soot particles within the upwardly rising smoke column are forcedoutwardly onto the inner wall 20 of the collector where a wall of watercaptures and entrains these particles and washes them'downwardly intothe scavenging trough 62. The water particles entrained within theupwardly rising cleaned gases are then recovered in the trough 62 afterthey are forced through the slots 70 by the action of the impeller 22.Water which is still entrained in the gases leaving the outlet 18 isreturned by the batlles 74 to the water recovering cylinder 66.

It is now readily apparent that the present invention provides an easilyconstructed soot eliminator which will efiiciently remove soot particlesfrom a smoke column. The soot eliminator uses wash water techniques toprovide a maximum cleaning of the gaseous products and yet the sooteliminator can be mounted to a smoke dis charging apparatus along thenormal upward movement of the smoke column.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

I claim:

1. A soot eliminator comprising:

a hollow cylindrical soot collector having a bottom smoke receivinginlet, a top gas discharge outlet, and a gas column therebetween;

rotatable impeller means mounted within said collector for centrifugallythrowing soot particles from the gas column toward the inner wall of thecollector;

means mounted within said collector substantially adjacent to and'circumferentially along the inner periphery of the inner wall fordischarging wash water over said inner wall around the outer peripheryof the gas column so as to provide a peripheral wall of wash water aboutthe gas column for receiving said soot particles;

motor means connected to the impeller means for rotating said impellermeans;

means mounted within said collector above the water discharging meansfor trapping water particles and returning them to the water dischargingmeans;

means for forcing said water particles to the Water trapping means;

the means for forcing the soot to the inner wall and the means forforcing the water particles to the water trapping means is saidrotatable impeller; and

said water trapping means including:

an inner hollow cylinder concentrically mounted in a spaced relationshipwithin the collector;

the inner cylinder having longitudinal slots for receiving the waterparticles; and

the water discharging means opening into the space between the innerhollow cylinder and the collector opening for receiving water trapped insaid space.

2. A soot eliminator comprising:

a hollow cylindrical soot collector having a bottom smoke receivinginlet, a top gas discharge outlet, and a gas column therebetween;

impeller means mounted within said collector for centrifugally forcingsoot particles from the gas column toward the inner wall of thecollector; said impeller means including:

a central hub which extends in axial alignment along the collectorthroughout substantially the full length of said wall of wash water; and

a plurality of vanes mounted on said hub and extending along the hubthroughout substantially the full length of said wall of water;

means mounted within said collector substantially adjacent to andcircumferentially along the inner periphery of the inner wall fordischarging wash water over said inner wall around the outer peripheryof the gas column so as to provide a peripheral wall of wash water aboutthe gas column for receiving soot particles;

means mounted within said collector above the water discharging meansfor trapping water particles and returning them to the Water dischargingmeans;

an exit duct connected to the collectors top outlet for receiving thecleaned gas;

batlie means mounted within the exit duct for impeding any circularmotion of said gas;

motor means connected to the impeller means for rotating said impellermeans;

said Water discharge means including:

an annular header mounted about the collectors inner wall;

said annular header being open on a top side for receiving the trappedwater particles from the water trapping and returning means; and

an annular perforated tube also mounted about the collectors inner wallbelow the annular header and connected to the header for receiving washwater therefrom;

a wash water scavenging trough mounted about the collectors inner wallnear the bottom inlet for receiving the soot filled wash water;

said water trapping means including:

an inner hollow cylinder concentrically mounted in a spaced relationshipwithin the collector; the inner cylinder having longitudinal slots forreceiving the water particles; and the space between the inner hollowcylinder and the collector opening into the water discharging means. 3.A soot eliminator as claimed in claim 2 wherein: said impeller meansextends into said inner hollow cylinder for centrifugally forcing thewater particles through the slots of the inner hollow cylinder. 4. Asoot eliminator as claimed in claim 3 including: a wash water scavengingtrough mounted about the :collectors inner wall near the bottom inletfor receiving the soot filled wash water.

References Cited UNITED STATES PATENTS 793,110 6/1905 Uehling -2401,447,554 3/1923 Jones 55-406 2,453,593 11/ 1948 Putney 55-408 3,336,7338/1967 Wisting 55-228 2,213,881 9/1940 Lauer 55-223 2,256,524 9/ 1941McKelvey 55-184 3,064,411 11/1962 Breslove 55-416 3,191,364 6/ 1965Sylvan 55-257 3,234,993 2/ 1966 Belcher 55-406 FOREIGN PATENTS 359,73910/ 1931 Great Britain.

704,898 3/ 1931 France.

HARRY B. THORNTON, Primary Examiner.

B. NOZICK, Assistant Examiner.

